Field of the Invention
The present invention relates to an image pickup system, and more particularly, to an image pickup system configured to carry out communication between modules that operate with different power supplies so as to stably operate the modules.
Description of the Related Art
Hitherto, a terminal is formed between a camera body and a lens barrel connected thereto, which enables supply of power from the camera body to the lens barrel and transfer of positional information of, for example, an optical member formed in the lens barrel. On the other hand, a driving unit connected to the lens barrel includes a motor for driving the optical member formed in the lens barrel and a sensor for positional detection of the optical member, and further includes a unit for securing power supply for operating the motor and the sensor.
For example, Japanese Patent Application Laid-Open No. H09-258293 discloses a technology in which a terminal is provided at a connecting portion between the camera body and the lens barrel for supply of power to the lens barrel and for transfer of information on the lens barrel. Further, Japanese Patent Application Laid-Open No. 2011-257542 discloses a technology in which a commercial power supply is connected to the driving unit to drive the optical member formed in the lens barrel.
In this case, when a position sensor is not formed in the lens barrel, the lens barrel cannot transfer the positional information to the camera body. On the other hand, a position sensor is formed in the driving unit that can be connected to the lens barrel. Therefore, the lens barrel can transfer the positional information to the camera body by transferring information obtained by the position sensor to the lens barrel.
However, when wired communication is carried out between the lens barrel and the driving unit, GNDs of different power supplies are connected to each other, which may cause unstable operation of the lens barrel and the driving unit, leading to a malfunction.